Definition
A unit of speed equal to one nautical mile per hour, or approximately 1.15 statute miles per hour. Knots are the standard unit of speed used in aviation and marine navigation for airspeed, ground speed, and wind speed.
Plain English
A way of measuring how fast something is moving, used in flying and sailing. One knot means you are travelling one nautical mile every hour. It is a little faster than one regular (statute) mile per hour.
Context Anchor
Seen on airspeed indicators, weather reports, flight plans, and performance charts.
Derivation
The term comes from old sailing practice. Sailors measured a ship's speed by trailing a rope behind the boat with knots tied at regular intervals. They counted how many knots passed through their hands in a fixed time. The word stuck, and the unit moved from sea to air.
Why Pilots Care
Virtually all airspeeds, groundspeeds, and wind reports are expressed in knots; confusing them with miles per hour leads to incorrect performance calculations.
Analogy
Think of knots as aviation’s version of miles per hour, but based on nautical miles instead of road miles.
Intuition Check
Knot does not mean a tied loop in a rope here. In aviation, a knot is a speed unit: one nautical mile per hour.
Example Sentence 1
The winds aloft forecast called for a headwind of 25 knots at our cruising altitude.
Example Sentence 2
The reported surface wind was 8 knots from 270 degrees.